Power-transmission mechanism.



E. A. HALBLEIB. POWER TRANSMISSION MECHANISM.

APPLICATION FILED FEB. 8, 1913.'

Patented June 30, 1914.

2 SHEETS-"SHEET 1.

3 O 37 o 2 a 24 kw" 27 31 I4 W wfimmcg sw a 22. lltmvmnmumf WI! 571 4 LTBMA E. A. HALBLEIB.

POWER TRANSMISSION MECHANISM.

APPLICATION FILED FEB. 8, 1913.

" 2 SHEETS-SHEET 2.

Patented. June 30, 1914 [[[mvmnmm EDWARD A. HALBLEIB, OF ROCHESTER, NEW YORK, ASSZGNOE NORTH EAST ELEC- TRIC COMPANY, ROCHESTER, NEW YORK, A; OURPGBATION OF NEW YORK.

POWER-TRANSMISSION MECEANISIVZ.

LEQLSSZ O To all whom it may concern:

Be it known that I, EDWARD A; HALBLEIB, a citizen of theUnitedStates, and resident of Rochester, in the county of Monroe and 'State of New York, have invented certain Theinvention is particularly designed for.

use imconnection with apparatus associated with an internal-combustion engine, such apparatus including a prime-mover, such as an electric generator, which may operate either as a dynamo, when actuated by the engine, or as a motor to provide powerfor starting the engine from a condition of rest. Such an apparatus is disclosed, for example, in my pending application, filed November 6,1911, Serial No. 658,902, and the present invention comprises various improvements in the power-transmission mechanism disclosed in said application. Power-transmissionmechanism of the type in question usuallyjcom'prises two rotary elements or shafts which may be connected, respectively, with theprime-movers, together with clutches for controllingthe cooperative relation of these elements; and in the case of mechanism adapted for use in connection with an electric motor-generator it also usually comjplises speed-changing gearing, controlled by rot ry elements may be changed according theglutches, whereby the speed-ratio of the ast ing-element.

,One object of the present invent on s to produce a mechanism, including clutches and gearing for the purposes referred to, of

simple, compact and eflicient form, and to this end I employ, among other features of construction and arrangement, a gearing in which an axiallyemovableclutch-member is employed, in the manner hereinafter set forth, in place of one or more of the automatic one-direction clutches employed in the mechanism of said application.

; Another object of the inventionis to pro duce a mechanism in which one of the rotary Specification of Letters Patent.

' secondary element.

he one or the other constitutes the driv- Patented June 34), Bri e Application filedFebruary 8, 1913. Serial No. 747,185.

elements, which may be designated, for convenience, as the secondary element, cannot, under any circumstances, act as a source of power for actuating the other or primary rotary element when the mechanism is set or adjusted :for operation in the opposite directionthat is, to permit power to be transmitted from the primary element to the This arrangement is particularly useful when the secondary element is connected with an electric generator as in said application, since it provides that if, owing to the low speed of the engine, the generator tends to overrun the engine as a result of return-flow of current from a storage-battery normally charged by the generator such overrunning of the generator is entirely free so that an effective counterelectromotive force may be produced in the generator wherebysuch return-flow of current is resisted and limited. To this end the invention comprises mechanism in which a novel arrangement of clutches is employed in the manner hereinafter set forth.

A further object of the invention is to provide, in connection with a. transmissionmechanism including a movable clutchmember, and with a controlling-device for controlling the generation of power by one of the prime-movers connected by the transmission-mechanism, -mechanism for operatively connecting the transmission-mechanism and the controlling-device in such a warmer that the latter acts to throw said prime-mover into or out of operation, as a source of power, only when the clutch-elementsare effectively engaged in one of their operative positions, and not in the intermediate disengaged positionsof the clutchelements. To this end the invention comprises mechanism which is hereinafter particularly described as employed to actuate the contact-devices of an electric circuitcontroller connected with a motor-generator, but which may obviouslybe employed as well to actuate controlling-devices of other kinds according to the nature of the primemover to be controlled.

Other objects and features of the invention will be set forth hereinafter, in connection with the description of the preferred embodiment of the invention.

In the accompanying drawings :Figure 1 is a side-elevation, partly in vertical, median section, of power-transmission mecha- 2 is a detail-view, partly in vertical section,

showing particularly the form and arrangement .of the clutches of said mechanism; Fig. 3 is a vertical section on the line 33 in Fig. 1; Fig. 4 is a vertical section, on a larger scale, on the line 44 in Fig. 1;

and Fig. 5 is a horizontal section on the line 55 in Fig. 4.

The invention is illustrated as employed in connection with engine-starting apparatus of the type disclosed in my said application, this apparatus including an electric generator 10, of which the construction is not particularly illustrated as it may be any ordinary or suitable form of direct-current generator, provided it is adapted to operate also as a motor when energized by current from a suitable source. -Although the generator, in the operation of the apparatus, acts also as a motor, it will hereinafter, for convenience, be referred to simply as a generator. The armature-shaft 11 of the generator is arranged in alinement with a shaft 12 which constitutes, in effect, a con tinuation of the armature-shaft, but which is connected, for convenience, with the latter by means of a yielding coupling 13 of the well-known Oldham form. A third shaft 14, which is arranged in axial alinement with the shaft 12, is adapted to be connected rotatably, in any convenient manner, with the crank-shaft of the engine in connection with which the apparatus may be employed. For convenience the two shafts 12 and 14 are hereinafter designated, respectively, as

the secondary rotary element and the primary rotary element, although, under the various conditions of operation, either one or the other may act as the driving element and the other as the driven element.

The shaft 12 is supported indirectly by a ball-bearing l5, and the shaft 14 is supported-by a pair of ball-bearings 16, these bearings all being mounted in a gear-casing 17 which is connected rigidly, by means of a frame-member 18, with the casing of the generator; The left-hand end of the shaft 12 is further supported by means of an integral extension 19 journaled in a recess in the shaft 14. This extension also provides -a thrust-bearing to prevent longitudinal clutch-member 22 is provided, at its leftmovement of the shaft 12 towardthe left. The shaft 12 is provided with an interme diate squared portion 21 which engages a central opening of similar form through a clutch-member 22, this member being thereby mounted upon the shaft so as to rotate in unison therewith, while free for longitudinal movement upon the portion 21. The

hand face, with a series of beveled clutchteeth 23 which are adapted to cooperate with similar teeth 24 formed in a shell or enlargement 25 at the right-hand end of the shaft 14. Accordingly, in the position or the parts illustrated in Figs. 1 and 2, the shaft 14, rotating in the direction indicated by the arrow in Fig. 1, may actuate the shaft- 12 in the same direction and at the same speed, thus driving the generator and cans ing it to generate electricity. This is the normal position of the apparatus when employed in connection with a hydrocarbon engine in an enginestarting system, the generator being actuated, provided the engine is in operation, both to recharge the storagebattery and to supply current for any trans- .lating-devices, such as electric lights, which may be connected with the system.

In order that the generator may elfectively actuate and start the engine. when necessary, speed-reducing gearing is provided through which the secondary rotary element or shaft 12 may drive the primary rotary element or shaft 14. To throw this gearing into or out of operation, as required, the sliding clutch-member 22 is provided, at its right-hand face, with a sec ond series of beveled clutch-teeth 26 which are adapted to cooperate with similar teeth 27 formed at the end of a sleeve 28. member 22 thus constitutes, integrally, elements of two distinct clutches. The sleeve 28 rotates loosely upon the shaft 1.2 and is supported directly by the ball-bearing 15,

while it hasa bearing bushing 29 to engage the shaft 12. The shaft and the sleeve are thus free to rotate independently of each other, while supported in common by the ball-bearing 15 which also serves to prevent endwise motion of the sleeve. In ad dition to the clutch-teeth 27 the sleeve 28 is provided with peripheral gear-teeth 81, so that it constitutes a pinion, and these teeth are constantly in mesh with the teeth of a large gear 32 which is journaled upon a shaft 33 fixed in the geancasing parallel with the shafts 12 and 14. Integral with the gear 32 is. a pinion 34 which meshes, in turn, with a gear co-axial'with the shafts 12 and 14. The gear 35 is annular in form, and it is mounted upon the shell 25 through the intermediation of rolling clutch-members. As shown in Fig. 3 the gear 35 is provided with a smooth inner clutch-surface 36 whereby it constitutes an element of a onedirection clutch. The other element of this clutch is the shell 25, which is provided with a series of inclined pockets 38. In these pockets are hardened rollers 37 which are pressed toward the shallow ends of the peak ets by springs 39, and which act, in a wellknown manner, to grip against the surface 36 so as automatically to prevent relative rotation of the gear 35 in a left-hand direction upon the shell 25. The arrangement just described constitutes, therefore, an automatic one-direction clutch through which the gear 35, rotating in the direction of the.

The

menses this arrangement permits the shaft 14 at any time to overrun the gear 35.

When the sliding clutch-member 22 is moved to disengage the gear-teeth 24 and engage the teeth on the sleeve 28, rotation of the shaft 12 is'the direction of the arrow applied to it in Fig. 1 causes rotation of the sleeve 28, which,'through the speed-reducing gearing and the one-direction clutch above described, causes rotation of the shaft 14 in the same direction but at a lower speed, and

this operation of the mechanism is employed to start the engine, connected with the shaft 14, from a position of rest. As soon as the engine begins to operate unden its own power, however, and at a sufficient speed of rotation, it tends tooverrun the gearing, as is permitted by the one-direction clutch as above described, and the sliding clutchmember 22 may then be returned to normal position to disconnect the gearing and couple the shaft 14 directly with the shaft 12. To

operate the sliding clutch-member 22 as above described, I illustrate means which act under manual control. The clutch-memher 22 is rovided with a peripheral flange 41 which 1s embraced by the segmental slotted end of an arm 42. This arm is fixed upon a slide-rod 43 which is arranged to slide in the gear casing parallel with the shafts 12 and 14. A compression-spring'44,

coiled about the rod 43, acts normally to hold the parts in the position of Fig. 1, but by sliding the rod to the right, against the op position of the spring, the arm 42 may be caused to move the clutch-member 22 to the rightas above described. To actuate the arm and the slide-rod a second arm 45 is fixed to the lower end of a shaft 46, which is journaled in vertical position at the upper part of the casing. This part of the casing, indicated by the reference-number 47, may be'designated as the switch-casing, since it incloses the elements of an electric switch. The shaft 46 passes, near its lower end, through a stufiingbox 48 which prevents the escape of oil from the gear-casing to the switch-casing. The upper end 49 of the shaft 46 is reduced in diameter and journaled in a sleeve 50 which, in turn, is journaled in the cover 51 of the switch-casing. The sleeve 50 has a squared upward projection 52 upon which is fixed an arm 53. This arm may be connected with any suitable means, such as a push-rod 54, through which the arm and the parts connected therewith may be operated manually.

in a socket in the sleeve, while the lower end engages a socket formed in a flange 56 which rejects integrally from the shaft 46. Accor ingly, when the arm is swung in the direction indicatedbythe arrow in Fig. 1, the spring 55 is subjected to. a torsion which causes it to turn the shaft 46, whereupon the arm 45, through its engagement with the hub of the arm 42, forces the latter arm and the slide-rod 43 to theright, as shown in Fig. 1, in opposition to the pressure of the spring 44, thus shifting the sliding clutchelement 22 for the purpose above described. To return the parts to normal position a ten-I, sion-spring 57 is attached, at one end, to the arm 53, as shown in Fig. 1, the other end of this spring (not shown) being attached to any convenient fixed point.

When shifting the clutch-mechanism, as above described, to cause the generator to act as a source of power for actuating the en gine, it is necessary also to make certain changes in the electric circuits connected with the generator, whereby the generator is caused to act as a motor;'and the switchmechanism for this purpose is inclosed within the switch-casing 47 and is actuated by the sleeve 50. As shown particularly in Figs. 4 and 5, a base 60 of insulating material is fixed atthe bottom of the switchcasing 47, and this base'supports three fixed contact-members 58, 59 and 61. The movable contact-member comprises two contactfingers 62 and 63 which are adapted to co operate with the fixed contacts. These fingers are formed integral with a collar which surrounds the shaft 46 and which is fixed in an insulating-bushing 64. This bushing, in turn, is fixed on a sleeve 65 concentric with the shaft 46. The sleeve is free both to turn and to slide longitudinally upon the shaft, and the shaft, in turn, is free to slide longitudinally with respect to the stuffing box48 and the sleeve 50. Accordingly, the spring 55, in addition to its operation as a torsion-spring as above described, may also be employed, through its tendency to longitudinal expansion, as a means for maintaining the contact-members of the switch in firm engagement, since the thrust of the spring is transmitted, through the flange 56, to the sleeve 65, and thence to the contactfingers, thus causing the fingers to be pressed firmly against the fixed contacts and the .base 60 in all positions of the switch. This thrust is resisted in the opposite direction by means of a shoulder 66 on the sleeve 50, which engages a thrust bearing on the cover 51 of the switch-casing.

The several fixed contacts of the switch in Figs. 4 and 5, and the switch is maintained in this position by means of a tensionspring 72, of which one end is attached to an arm 71 projecting from the switch-sleeve 65, the other end of the spring being fixed to the switcli casing. In this normal position the contact-finger. 62 engages one of the fixed contacts 59, while the finger 63- engages the the sleeve 50.

insulating-base 60. The switch is thus normally in open-circuit position. The switch is moved to closed-circuit position by means of a segmental downward projection 7 3 on projection normally engages a lug 74 projecting upwardly from the switch-sleeve 65. Accordingly, when the sleeve is rotated in a clockwise direction to operate the clutch-mechanism as above described, the projection 73 pushes the lug 7 4 so as to cause a similar and equal rotation of the movable switch-member; parts are such that during this movement the sliding clutch-member 22 is moved fully into engagement witlrthe'clutch-teeth 27 before any circuit is closed by the switch. After the completion of this movement of the clutch-element, however, which causes the further rotation of the shaft 46 to be arrested, the rotation of the sleeve 50 may be continued, owing to' the yielding connection aflorded between the sleeve and the shaft by the spring 55, and this continued movement results in bringing the contactfinger 63 into engagement-with the fixed contact 58, thus closing the circuit between the fixed contacts 58 and 59, and the further continued movement of the sleeve 50 causes the contaet finger (32 finally to engage the fixed contact Gl as well, while the contact-finger 63 continues in engagement with the fixed contact 58, thus closing a further circuit. As above stated, the circuit-closing action of the switch, by which the generator is caused to act as a motor, does not occur until the clutch-member 22 has been shifted member has been brought fully back to normal position. Accordingly, means are provided for retaimng the switch agamst such return-movement until the proper moment.

' To this endthe sleeve 65 is provided with a toothed flange 7 5 which cotiperates with a hooked detent 76 pivoted upon a stud 77 in the switch-casing. A spring 7 8, coiled about. the stud and engaging the detent, tends to The right-hand end of this- The proportions of thethrow the detent into engagement with the toothed flange. Accordingly, after the switch-sleeve has been turned in a clockwise direction, it isretained in the position to which it has been turned until released fro the action of the'detent.

In order that the switch may be so released at the proper moment, the detent is provided with a release-arm 79 which is adapted to engage the left-hand extremity of the projection 73 on the sleeve 50. This engagement cannot occur until the sleeve 50 hasreturned nearly to its normal position. When it does occur, however, the detent is thrown into the inoperative position of Fig. 5, against the opposition of its spring 78, thus disengaging it from the switch-sleeve and permitting the spring 72 to return the switch to normal position. The detent is provided with a stop-lug 81 which engages the inner surface of the switch-casing, so that it is adapted to operate, through engagement with the projection 7 8, as a stop to determine the normal position of the switch, as shown in Fig. 5. Another advantage of the arrangement just described resides in the fact that it provides for a rapid return-movement or snap-action of the switch when moving in the direction to break the circuits which have been closed by it, this arrangement having the advantages well understood by those skilled in the art.

Owing to the-provision of a series of closely-spaced teeth on the switch-sleeve, to cooperate with the detent 76, the detent may act to arrest the switch not only inits ultimate circuit-closing position, but in any intermediate position to which it may be moved. This arrangement is of valueas it guards against danger .to the mechanism which might arise from careless and incorrect operation on the part of the operator. In the absence of this arrangement it would be possible to move the mechanism sulficiently to engage the sliding clutch-member 22 with the sleeve 28, and at the same time to move the switch to an intermediate circuitclosing position, and the operator might then carelessly permit the parts to return partly to normal position, thus opening the circuitsthroughthe generator, and disengaging the clutch-element 22 from the sleeve 28 without permitting it to reengage the clutch-teeth 24 In such a' case the generator would be both de'elnergized and disconnected from the shaft 14, so that it would come to rest. If the engine should be inoperation at such time it might then be possi ble to throw a severe strain upon the mechanism bypermittiug the clutch-member 22 to return into engagement with the clutchteeth 24, thus imposing upon the mechanism the duty of starting the generator suddenly into rapid rotation. The arrangement above described prevents this action, however, since LIQLEiEiS the switch, when once moved to circuit-closingposition, cannot return from that pos1 tion until released automatically, as above described, after the clutch-member 22 has returned fullytooperative connection with the shaft 14. Q

While I have described an electric switch as the device employed to control the production of power by the prime-mover embodied in the generator 170, it will be apparent that the arrangement by'which the action of the switch and of the clutch-mechanism is properly coordinated is applicable to; apparatus inwhich prime-movers of other typesare employed, the electric switch constituting merely a prototype of a controlling-device which may be adapted, in its character and construction, to the particularform of prime-mover employed in any given case, and therefore in the succeed= ing claims I have referred generally to a this term signifying either an electric'switch or any equivalent controllin -device, whether electrical or not.

In the use of an electric generator con- .nected with a storage-battery, asdisclosed in my .said application, the direction in which current tends to flow between the generator and the battery depends upon the relative'electromotive forces; of these parts.

. When the engine is operating at such a speed that the .electromotive' force produced by the generator is greater than that producedby the storage-battery, current tends to flow from the generator through the battery, thus recharging the battery. In case the speed. of the engine falls below a predetermined point, however, the electromotive force of the' generator becomes less than that of the battery,-and current tends to return from I the battery through the generator, thus causing the generator to act as a motor. To

prevent this return-flow of current under normal circumstances it has been common to employ, n storage-battery systems suchasare employed upon automobiles or railway-vehicles subject to wide-variations in the speed ofv their engines or other sources of motive power, a device in the nature of arelay which acts as an automatic cut-out to prevent, or substantially reduce, the returnflow of current. While such an arrangement -may be employed in connection with the powei mechanism herein disclosed, this mechamsm afiords an arrangement'which 1s well adapted to dispense with such a device where it is considered undesirable for any reason. It' will be apparent'that the slidable clutch-member 22, owing to the fact that its clutch-teeth are beveled 111 one direction and that it is held in engagement with the clutch-teeth 24 only by the resilient ac tion of the spring 44, constitutes a yielding device or one-dlrection clutch, since it is substantially free at any time to overrun te shaft 14 by sliding to the right so as to. disengage its teeth from the teeth 24.- At the same time, since the speed-reducing gearing is entirely disconnected, operatively, from the generator-shaft while the generator is generating, it follows that whenever return-flow of current occurs from the bat over the teeth 24, cause abuzzing noise, and 1n this manner the operator may be warned to Operate any suit-able manual device for opening the charging-circuit between the generator and the battery.

Another advantage of the present mechanism resides in the fact that the mechanism is not locked, in any position, against reverse. rotation of the shaft 14. WVhere automatic one-direction clutches are employed as the sole means for controlling the power-mechanism this is not the case. By the use of the sliding clutch-member 22, however, which acts always to disengage one clutch when engaging the other, provision is made whereby a reverse rotation of the shaft 14, such as might be caused by a back-kick in the engine to which it isconnected, cannot result in injury to themechanism. If such reverse rotation occurs while in Fig. 1, the reduced-speed gearing and the sleeve 28 are merely rotated idly in a reverse direction, through the action of the one-directionclutch by which the shaft 14 and the gear 35 are connected, while the beveled teeth 24 and 23 slip idly by each other: On the other hand, if such reverse rotation occurs when the mechanism is in position for starting the engine, the movement is merely transmitted through the gearing to the sleeve 28, the clutch-element 22 and the shaft 12,- and a reverse rotation is imparted to the generator, which may easily occur owing to the comparatively slight inertia of the armature. In neither case can there be any interlocking action of the mechanism by which such reverse rotation can be positively arrested.

My invention is not limited to the embodiment thereof hereinbefore described and illustrated in the accompanying drawings. but it may be embodied in various other forms within the nature of the inven primary element'may actuate the secondaryelemcnt while the latter is free to overrun the former; means, including a second pair of clutch-members, through which the secondary rotary element may actuate the primary" rotary element; and manually-operable means .for throwing the second pair of clutch-members into and out of engagement.

2. In power-transmission mechanism comprising a'primary rotary element and a secondary rotary element; clutch-mechanism for operatively connecting said elements, including a one-direction clutch whereby the primary element may drive the secondary element; said mechanism being adapted, in diiferent operative positions, to afford a driving connection whereby the secondary element may actuate the primary'element, or

' whereby the primary element may actuate the secondary element, in the same direction of rotation, through said clutch while the secondary element is free to overrun the primary element, or to permit the primary ele ment to rotate freely in a reverse direction.

3. Power-transmission mechanism having, in combination with a primary rotary element and. a secondary rotary element; a clutch for connecting said elements to permit the primary element to actuate the secondary element; and means, for connectmg said elements to permit'the sec- "ondary element to actuate the primary element, in the same direction of rotation, said means including speed-reducing gearing, an automatic one-direction clutch connecting the gearing with the primary rotary element, and a clutch adapted to be thrown out of position for operation in either direction, whereby the primary element is left free to rotate in either directionx 4c. Power-transmission mechanism having,

in combination with a primary rotary element and a secondary rotary element; a onedirection clutch for connecting said elements to permit the primary element to actuate the secondary element while leaving the secondary element free to overrun; and means, including speed-reducinggearing, for con- 'necting said elements to permit the secondary element to actuate the primary element, in the same direction of rotation, said means including als aclutch adapted to be thrown to a position in which it is ineperative in either direction, whereby the primary element is lei-f to rotate ei ily ot led me for throwing the last-menti 3d clutch at of operation.

5. Power-transmission mechanism having, in combination with a primary rotary element and a secondary rotary element; speedreducing gearing and an automatic onedirection clutch adapted to rotate the primary element; and manually-controlled clutch-mechanism adapted, in alternative positions, to couple the secondary element with said gearing to actuate the primary element,- or to couple the primary element with the secondary element to actuatev the latter independently of the gearing.

6. Power-transmission mechanism having, in combination with a primary rotary element and a secondary rotary element; a onedirection clutch for connecting said elements, whereby the primary element'may actuate the secondary element; gearing connected with the primary element; a clutch for connecting said gearing with the secondary element, whereby the latter element may actuate the primary element; and means for holding the last-mentioned clutch out of operative position, whereby the secondary element may be left free to overrun the primary element.

7. Power-transmission mechanism having, in combination with two rotary elements; means, including clutch-mechanism for connecting said elements, whereby they may actuate each other alternatively, according to the position of the clutch-mechanism; manually-controlled means for moving the clutch-mechanism for such alternative operation; and a power-controller having a lost-motion connection with said manuallycontrolled means whereby the; controller is moved to operate after the manually-controlled means have moved the clutch-mechanism from one alternative position to the other.

8. Power-transmission mechanism having, in combination, a primary rotary element and a secondary rotary element co-axially ournaled; a pinion concentric with the secondary element and provided with clutchteeth; a set of clutch-teeth on the primary element; a clutch-member mounted to slide, but not rotate, on the secondary element and having, on opposite faces, teeth adapted to cooperate with the before-mentioned sets of teeth alternatively; said rotary elements r0- tating normally in the same direction of rotation and the clutclrteeth on the primary element being inclined in a direction to permit the secondary element to overrun in the normal direction of rotation; a gear coaxial with the primary rotary element and connected therewith by a one-direction cluich to permit the primary element to rrnal d ection of rotation; gearing connecting said F 0. gear to permit the secondment to dive the primary ront through said onedirection mission mechanism having,

I in combination, a primary rotary element; a secondary rotary element adapted to be connected with a source ofpower; a controller for said source of power; gearing and cl utclrmeclianism forconnecting the roation according as the secondary ro tary element constitutes the driving element or the,

driven element, aid mechanism being adapted to delay the operation of the power controller, in each direction, until the clutchmechanism has been moved from one operative position to'the other.

ing, in combination, a primary rotary elevrment; a secondaryrotary element adapted to be connected with a sourceof power; a controller for said source of-power ygearing and clutch-mechanism for connecting the rotary elements to permit them to actuate each "other, alternatively, in the same direction otrotation, according to the position of the clutch-mechanism; means for moving the clutch-mechanism for such alternative operation; and mechanism, actuated by said means, for moving the controller to throw said source of power into or out of operation according as th e secondary rotary element constitutes the driving element or the driven element, said mechanism being adapted to delay the operation of the ower controller, in each direction, until t e clutch-mechanism has been moved from one operative position to the other, and to prevent a retro grade movement of the power-controller, in the direction to shut off the power, after it has been moved in the opposite direction, until the clutch-mechanism has been re turned to a position in which the primary rotary element can actuate the secondary rotary element.

11. Power-transmission mechanism having, iIl combination with a primary rotary element and a secondary rotary element, means, including a one-direction clutch, through which'the primaryrotary element may actuate the secondary rotary element while the latter is free to overrun; means, iricluding a one-directicnoclutch, through which the secondary rotary element may actuate the primary rotary element, while the latter is free to overrun; and manually- Q operable means tor throwing one of said 10. Power-transmission mechanism hav- .clutches into or out of operation according as one or the other of the rotary elements is to constitute the driver.

12. Power-transmission mechanism having, in combination with a primary rotary element and a secondary rotary element, means, including a onedirection clutch, through which the primary rotary element may actuate the secondary rotary element, while the latter is free to overrun; drivingm eans through which the secondary rotary element may actuate the primary rotary element; and manually operable means for throwing said driving-means into or out of operation as one or the other of the rotary elements is to constitute the driver.

.EDVVARD A. HALBLEIB. Witnesses: v

FARNUM F. DoRsEY, 

